In recent years, progress has been made by increasing the speed and improving the image quality of color photographic photographic materials in response to the requirements of the user. With respect to the improvement of picture quality, progress has been made in the main with improvement of color reproduction, improvement of sharpness and improvement of graininess. These factors are of great importance when comparing the performance cf photographic materials, and it is clear that further improvement will be required in the future.
The dyes which are formed with the yellow, magenta and cyan couplers which have been used in silver halide color photographic materials in the past have tended to impair color reproduction because of unwanted auxiliary absorbances. Hence, couplers which form colored images with little auxiliary absorption have been subject to research as a means of improving color reproduction.
With magenta dyes, improvement of the magenta hue has been achieved by the use of pyrazoloazole based magenta couplers in place of the conventional 5-pyrazolone type magenta couplers. The azomethine dyes formed by reaction between these couplers and the oxidation products of color developing agents have a high saturation because there is little auxiliary absorption in the region of 430 nm which is deleterious with respect to color reproduction and it is known that these are desirable from the viewpoint of color reproduction. Such couplers have been disclosed, for example, in U.S. Pat. No. 3,725,067, JP-A-60-172982, JP-A-60-33552, JP-A-61-72238, U.S. Pat. Nos. 4,500,630 and 4,540,654. (The term "JP-A" as used herein signifies an "unexamined published Japanese patent application".)
Furthermore, in the past the yellow couplers have provided low saturation and improvement by sharpening the spectral absorption is very desirable. On the other hand, reduction of the film thickness of photographic materials is required to improve sharpness, but this requires the use of couplers which have good color forming properties in the emulsion layers and their emulsification and dispersion in a stable manner with a reduced quantity of high boiling point organic solvent. The yellow couplers from which the dyes are formed have a sharp absorption spectrum, they have excellent color reproduction and there is little variation in the color forming properties with changes in the pH of the color developer disclosed in JP-A-63-123047, for example, can be cited as couplers of this type.
However, according to observations made by the present inventors, the formation of the respective colored dyes when the above mentioned yellow couplers and pyrazoloazole based magenta couplers are used conjointly varies greatly depending on slight fluctuations in the pH of the color developer and color mixing and color staining occurs as a result of interlayer mixing of the oxidized developing agent into other layers. The resolution of these problems is desirable.